Rubber mattress



March 5, 1940. l N. D. MA'r'rlsoN RUBBER MATTRESS Filed June 8; 19.39

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ATTORNEY March 5, N. D.' MAT-rlsN RUBBER MATTRESS .A

Filed June 8. 1959 Iall. IuIlII ATTORNEY Patented Mar.'5, 1940 UNITEDSTATES PATENT oFFrcE RUBBER MATTRESS Norman D. Mattison, Montclair, N.J. Application June 8, 1939, Serial No. 278,025

3 Claims. (Cl. 5355) This invention relates to rubber mattresses andmore particularly to mattresses made of spongelike rubber. Rubber ofthis sort made from liquid latex is at the present time offered as a 5commercial product for use as a cushioning material for mattresses,cushions, pads and the like.

An object of the present invention is to utilize a rubber mattress ofthe type described which will fulfill the requirements necessary tocomfortable and restful sleep and winch will require but little changein standard methods of manufacturing a mattress of this type.

Rubber mattresses as commercially offered to the trade are of cellularstructure, the cells all being of substantially equal capacity and aredistributed substantially uniformly throughout the mattress. These cellsare open at the bottom of the mattress but do not extend completelythrough it, there being a layer of sponge-like rubber between the upperportions of the cells and the top surface of the mattress. Such amattress is therefore a one surface mattress and is not intended to beturned bottom side up. As described in my application, Serial No.269,834 filed April 25, 1939, for Spring mattress, the factor ofsoftness or yield of a mattress is only one of the factors which areconducive to comfort in sleeping. The other factor, as I have foundbynumerous experiments, is the ease with which the individual may turnover or change position. Considered solely from the viewpoint offacilitating changes in position, a hard fiat surface seems to be thebest. Such a surface, however, is not comfortable and in the manufactureof mattresses heretofore as far as I am aware, efforts to increase thesoftness have been made while neglecting the other factor, namely theease in changing position or turning over. In the rubber mattresses suchas are offered to the trade at the present time, insofar as I am aware,the supporting surface of the mattress has approximately a uniformdegree of resilience, "since the cells are of the same capacitythroughout and are substantially equally distributed.

With such a. mattress the resistance to depression is substantially thesame for a given weight or-load per square footof area throughoutapproximately the entire surface of the mattress. 60 However, since arelatively large proportion of the weight of the body is located in themidsection, that is, in the region of the hips, the central part of arubber mattress of the present commercial type is depressed to a greaterdegree 55 in mid-section than in adjacent sections. The

result is a tendency of the mattress to sag in the middle which sagginginduces a condition which many users find uncomfortable due to the factthat it throws the spinal column-out of line. It also increases theeffort to turn over in bed. i

In .my application above referred to, I have disclosed a construction ofspring mattress in which greater resistance is oil'ered to the body inthe mid-section of the mattress.

The present invention seeks to provide for a 10 similark condition inrubber mattresses.

In the accompanying drawings several forms, whereby the desired resultmay be accomplished, are shown. In said drawings:

Figure 1 is a top plan view with a portionof the upper surface brokenaway to more clearly show the cellular structure;

Figure 2 is a section on the line 2-2 of Figure Figure 3 is a somewhatenlarged view of one 20 of the plugs used in connection with this formof construction;

Figure 4 is a view similar to Figure 1 but showing a different formwhich the invention may take; 5

Figure 5 is a section on the line 5-5 of Figure Figure 6 is a viewsimilar to Figure 1 showing still another form which the invention maytake; and 3 Figure 7 is a section on the line 1-1 of Figure 6.

Referring to the drawings, the mattress 2, is

formed of sponge-like rubber and preferably of rubber made from liquidlatex, and made spongy 35' in any desired manner, preferably by mixingair with the latex before molding. The rubber forming the mattress is ofsubstantially equal unit density. In order that such a mattress may havethe resilience usually desired, a number of cells 40 4 are formed duringthe molding process. These cells are open at the bottom and extend to adistance near the upper surface of the mattress but leaving a layerindicated at B between the upper portions of the cells and the upperface 45 of the'mattress.

In the form of mattress illustrated in Figure 1, I increase theresistance of the mid-portion of the mattress by inserting a number ofplugs 8 in the cells composing this mid-portion. One of these plugs isshown in Figure 3. In the Figure 1 construction, all of the cells may beof the same dimensions and may be equally distributed since thisconstruction conforms to the standard methods of manufacture. The plugs8, however, Il

may be inserted in all of the cells of the ber of cells. By the use ofthese plugs, therefore, I provide a means whereby the resistance,especially that which the mid-section of the mattress oilers, may bevaried in a standard mattress. The mid-section is not necessarily inthemiddle of the mattress, but is nearer to the head than to the foot andmay extend a distance between 16 and 22 inches, although I have found 18inches to be a practical dimension and I have shown this dimension onthe drawings. With this dimension for the mid-section, the head sectionwould be 23 inches and the foot section 31 inches, in a standardmattress of 'l2 inches in length. This mid-section extends transverselythe entire width of the mattress but is of limited longitudinal extent.

While the construction shown in Figure 1 enables the resistance to bevaried, at will to suit individuals of different weights, the inventionmay nevertheless rind utilityin a mattress of denite resistance in itsmid-section and in Figures 4 and 5 I have shown a construction in whichthe cells are all of th'e same size or capacity but are more widelyseparated in the mid-section than in the adjacent sections.

Still another way in which the same result can be produced as in theFigures 4 and 5 construction, is illustrated in Figures 6 and 'l whereinthe cells in the mid-section are smaller than in the adjacent sections.Preferably all of the cells are of the same depth but are of smallerdiameter in the mid-section.

InV all of the forms it will be observed that the quantity of rubber inthe mid-section is greater than in the adjacent sections. In otherwords, portions of the mattress of equal external dimensions havedifferent quantities of rubber therein.

In order to augment the resistance especially in a direction transverseof the mattress, I may embed a fabric Ill between the upper surface ofmidsection or they may be inserted in any less numthe mattress and theupper portions of the cells., This fabric may extend across the mattressonly in the mid-section, as shown, or it may extend throughout themattress or may be omitted entirely. l

A rubber mattress constructed as above described, provides asubstantially level surface when deformed by the weight of a personlying upon it in sleeping position and in the form of the invention asillustrated in Figures 1 and 2, the resistance especially in themid-section may be Varied as desired to adapt the resistance of suchmid-section to persons of different weights.

What I claim is:

1. A mattress of cellular structure made of sponge-like rubber ofsubstantially equal unit density, the cells of which are ofsubstantially the same dimensions, a portion of the mattress extendingtransversely the width of the same but occupying a limited longitudinalarea near the central portion thereof having removable plugs carried bythe cells thereof, said plugs being com- Aposed of rubber susbtantiallylike that of the mattress.

2. A mattress of cellular structure made of sponge-like rubber ofsubstantially equal unit density, the cells of which are allsubstantially of the same dimensions, a portion of the mattressextending transversely the width of the same but occupying a limitedlongitudinal area near the central portion thereof having cells morewidely spaced than the cells in other portions of the mattress of equalexternal dimensions.

3. A mattress of cellular structure made of sponge-like rubber ofsubstantially equal unit density, the cells of which are ofsubstantially the same dimensions, removable plugs adapted to beinserted in the cells of said mattress whereby different portions of thesame may be given different resistances to pressure.

NORMAN' D. MA'I'I'ISON.

